The doctrine of command responsibility was developed and applied to both military and civilian superiors at the Nuremberg and Tokyo trials. It received conventional acceptance in articles 86 and 87 of Additional Protocol I to the Geneva Conventions, and is widely incorporated into national military manuals. Whatever the doubts embedded in its origins, there is no dispute today as to command responsibility's status in treaty and customary international law. It creates a specific form of omissions liability for superiors - military and civilian - who fail to prevent or punish the crimes of their subordinates. This chapter provides an overview of the doctrine of command responsibility and asseses its constituent elements, uncontested and contested.